Portable lamp



FIG. 1 is a perspective view of a portable lamp showing my new design;

FIG. 2 is a top plan view;

FIG. 3 is an elevational view;

FIG. 4 is an elevational view looking from the left of FIG. 3;

FIG. 5 is an elevational view looking from the right of FIG. 3; and

FIG. 6 is a bottom plan view thereof. 

The ornamental design for a portable lamp, as shown. 